Portable communication devices comprising a movable element attached to an apparatus housing are known as such from e.g. EP-B-0 275 996, JP-A-08065368, JP-A-06303296, U.S. Pat. No. 5,384,844, U.S. Pat. No. 5,257,310 and EP-A-0 120 418. As seen in these prior art documents, portable communication devices as described above are available in many different kinds, such as mobile or cellular telephones, wireless telephone handsets, etc.
In the case of mobile telephones the movable element usually has the form of a flip, which is pivotally or slidably mounted, by means of for instance a hinge mechanism, to the main apparatus housing of the telephone. The flip is movable between two end positions. In the first position the flip is fully folded in or displaced in close proximity to a portion of the apparatus housing, normally the portion at which a key pad is located, the flip thereby protecting the key pad from accidental actuation. The second end position of the flip is a fully opened or extended position, wherein the entire front surface of the telephone is accessible to a user during e.g. ongoing calls. Furthermore, as is well known in the technical field, the mobile telephone comprises audio-generating means, such as a speaker with a voice coil and a magnet for exposing the voice coil to a magnetic field, and/or a buzzer (summer) for generating audio signals indicative of e.g. an incoming call. Additionally, the telephone may comprise an electrodynamic vibrator with a similar function.
It is often desired to detect the current position of the flip relative to the apparatus housing. For instance, the processor (CPU) of the mobile telephone may be arranged to control the enlightening of the display and the key pad, once the flip is moved from its closed position to its open or extended position. Additionally, when the flip is folded in from its open position, the processor may be arranged to control the termination of an ongoing call (i.e. to perform an on-hook operation). For the purpose of detecting the position of the flip and the reporting thereof to the processor, it is previously known to provide the mobile telephone with a magnetic sensor, such as a hall element or a reed switch, in the apparatus housing, while the flip is provided with a magnet. The location of the magnet in the flip relative to the hall element or reed switch in the apparatus housing is such that, when the flip is closed or folded in, the distance between the magnet and the magnetic sensor is short enough for the latter to detect the presence of the magnetic field generated by the former. On the other hand, when the flip is opened or folded out, the distance between the magnet and the magnetic sensor is considerably larger and particularly too large for the magnetic sensor to be able to detect the magnetic field from the magnet. Hence, in this way the mobile telephone is able to detect the position of the flip relative to the main apparatus housing.
The drawback of the prior art approach is that the need for a separate magnet in the flip implies a cost penalty as well as difficulties in mounting the magnet in a satisfactory way in the flip, since the magnet will have to be large enough for generating a sufficiently strong magnetic field.
U.S. Pat. No. 5,673,314 discloses a mobile telephone having a speaker with a magnet, both of which are located in the flip and are arranged to magnetically affect a switch located in the telephone housing. Hence, the magnetic field generated by the speaker magnet is used for detecting the position of the flip, wherein the need for a separate magnet is eliminated.
The drawback of the solution shown in U.S. Pat. No. 5,673,314 is that the location of the speaker in the flip requires electrical wiring between the telephone housing and the flip. Such electrical wiring is volnerable to e.g. dirt, moisture and mechanical damage.